Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2003
Severe Thunderstorm Watch 899
The Storm Prediction Center issued this severe thunderstorm watch at Aug 27, 2003, 9:40 AM EDT for Harford County, Maryland; 37 counties in Pennsylvania. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 27, 2003, 9:40 AM EDT (13:40 UTC)
- Expired
- Aug 27, 2003, 3:00 PM EDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
All 38 counties
Harford County, MD, Adams County, PA, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Bedford County, PA, Blair County, PA, Butler County, PA, Cambria County, PA, Centre County, PA, Clarion County, PA, Clearfield County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Fayette County, PA, Franklin County, PA, Fulton County, PA, Greene County, PA, Huntingdon County, PA, Indiana County, PA, Jefferson County, PA, Juniata County, PA, Lancaster County, PA, Lawrence County, PA, Lebanon County, PA, Mercer County, PA, Mifflin County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, Union County, PA, Washington County, PA, Westmoreland County, PA, York County, PA
The radar
The State College radar (KCCX), 68 km from the middle of the area, began a volume at 13:42 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
Warnings issued inside it
10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 27, 9:43 AM EDT | Severe Thunderstorm Warning | CTP | Clearfield | 62 min |
| Aug 27, 9:53 AM EDT | Flash Flood Warning | PBZ | Washington | 3 hr |
| Aug 27, 9:58 AM EDT | Severe Thunderstorm Warning | CTP | Blair | 17 min |
| Aug 27, 10:04 AM EDT | Flash Flood Warning | PBZ | Westmoreland | 3 hr |
| Aug 27, 10:05 AM EDT | Severe Thunderstorm Warning | CTP | Centre | 70 min |
| Aug 27, 10:15 AM EDT | Severe Thunderstorm Warning | CTP | Huntingdon | 45 min |
| Aug 27, 10:18 AM EDT | Severe Thunderstorm Warning | PBZ | Westmoreland | 42 min |
| Aug 27, 10:27 AM EDT | Severe Thunderstorm Warning | CTP | Blair | 18 min |
| Aug 27, 10:42 AM EDT | Severe Thunderstorm Warning | CTP | Mifflin | 33 min |
| Aug 27, 2:57 PM EDT | Severe Thunderstorm Warning | PBZ | Greene | 48 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Pittsburgh, PA (KPIT), launched 12:00Z, 1.7 hours before the alert went out and 120 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 1234 J/kg
- Mixed-layer CIN
- -53 J/kg
- Mixed-layer LCL
- 728 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 107 m²/s²
- 0-3 km storm-relative helicity
- 172 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.2
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 9:20 PM EDT | Severe Thunderstorm Watch | SPC | Allegany, Garrett | 6 hr |
| Aug 26, 10:18 PM EDT | Mesoscale Discussion | SPC | Allegany, Garrett | 57 min |
| Aug 27, 12:22 AM EDT | Mesoscale Discussion | SPC | Charles | 53 min |
| Aug 27, 6:11 AM EDT | Mesoscale Discussion | SPC | Allegany, Garrett, Washington | 2 hr |
| Aug 27, 9:23 AM EDT | Mesoscale Discussion | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll and 17 more | 2 hr |
| Aug 27, 10:35 AM EDT | Severe Thunderstorm Watch | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more | 5 hr |
| Aug 27, 2:10 PM EDT | Mesoscale Discussion | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more | 65 min |
| Aug 27, 3:09 PM EDT | Mesoscale Discussion | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Frederick and 7 more | 66 min |
| Aug 27, 3:30 PM EDT | Severe Thunderstorm Watch | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 9 more | 7 hr |
| Aug 27, 5:03 PM EDT | Mesoscale Discussion | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 10 more | 87 min |
| Aug 27, 6:56 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 15 more | 64 min |
| Aug 27, 7:30 PM EDT | Severe Thunderstorm Watch | SPC | Caroline, Cecil, Dorchester, Kent, Queen Anne's, Somerset and 3 more | 4 hr |
| Aug 27, 11:48 AM EDT | Mesoscale Discussion | SPC | Adams, Allegheny, Beaver, Bedford, Cambria, Columbia and 18 more | 87 min |
| Aug 27, 2:05 PM EDT | Severe Thunderstorm Watch | SPC | Fayette, Greene, Washington, Westmoreland | 5 hr |
Nearby
Severe Thunderstorm Watches in Pennsylvania, 2003Severe Thunderstorm Watches in Maryland, 2003Every severe thunderstorm watch in 2003
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.